Take this as a hard lesson learned. "Trust, but verify" should be modus operandi. You really should distance yourself from this guy, since he's acting maliciou

Take this as a hard lesson learned. "Trust, but verify" should be modus operandi. You really should distance yourself from this guy, since he's acting maliciously. Badmouthing him to random people isn't really productive for you either. As a consolation, his lies will eventually catch up to him because people who have been burned before will quickly recognize the signs. Remove your affiliation from the company. You were a freelance consultant for all the product and technical parts. That's how you should explain the experience. You left a PhD program to pursue a tempting opportunity of increased responsibility in a fast paced environment, with potentially large impact. It didn't turn out as you had hoped. The due diligence in a lot of these places is pretty bad anyways, so you likely will never be questioned about personal conflicts at this startup.